harmony 鸿蒙使用Node-API调用返回值为promise的ArkTS方法

2025-06-12
浏览 (3)

使用Node-API调用返回值为promise的ArkTS方法

场景介绍

当ArkTS的返回值为promise，开发者可以按照以下方式在自己创建的ArkTS运行环境中调用异步的ArkTS接口。

调用异步的ArkTS接口示例

从c++使用NAPI调用返回Promise的ArkTS方法。处理Promise对象：将Promise与c++回调绑定，处理异步结果。转换数据类型：在回调中将JavaScript结果转换为c++可用的数据。线程安全处理：确保跨线程操作的安全性。

示例代码

模块注册

#include "hilog/log.h"
#include "napi/native_api.h"
#include <napi/common.h>
#include <pthread.h>


//解析Promise结果的回调
static napi_value ResolvedCallback(napi_env env, napi_callback_info info)
{
    size_t argc = 1;
    napi_value args[1];
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);


    int result;
    napi_get_value_int32(env, args[0], &result);
    OH_LOG_INFO(LOG_APP, "Promise resolved with result:%{public}d", result);
    return nullptr;
}


//拒绝Promise的回调
static napi_value RejectedCallback(napi_env env, napi_callback_info info)
{
    size_t argc = 1;
    napi_value args[1];
    napi_get_cb_info(env, info, &argc, args, nullptr, nullptr);


    napi_value error;
    napi_coerce_to_string(env, args[0], &error);
    char errorMsg[1024];
    size_t len;
    napi_get_value_string_utf8(env, error, errorMsg, sizeof(errorMsg), &len);
    OH_LOG_ERROR(LOG_APP, "Promise rejected with error:%{public}s", errorMsg);
    return nullptr;
}


static napi_value CallArkTSAsync(napi_env env, napi_callback_info info)
{
    size_t argc = 1;
    napi_value argv[1] = { nullptr };
    napi_get_cb_info(env, info, &argc, argv, nullptr, nullptr);
    napi_value promise = nullptr;
    napi_call_function(env, nullptr, argv[0], 0, nullptr, &promise);


    napi_value thenFunc = nullptr;
    if (napi_get_named_property(env, promise, "then", &thenFunc) != napi_ok) {
        return nullptr;
    }


    napi_value onResolve = nullptr;
    napi_value onReject = nullptr;
    napi_create_function(env, "onResolve", NAPI_AUTO_LENGTH, ResolvedCallback, nullptr, &onResolve);
    napi_create_function(env, "onReject", NAPI_AUTO_LENGTH, RejectedCallback, nullptr, &onReject);
    napi_value argv1[2] = {onResolve, onReject};
    napi_call_function(env, promise, thenFunc, 2, argv1, nullptr);


    return nullptr;
}


// 注册模块接口
EXTERN_C_START
static napi_value Init(napi_env env, napi_value exports)
{
    napi_property_descriptor desc[] = {
        {"callArkTSAsync", nullptr, CallArkTSAsync, nullptr, nullptr, nullptr, napi_default, nullptr}
    };
    napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
    return exports;
}
EXTERN_C_END


static napi_module nativeModule = {
    .nm_version = 1,
    .nm_flags = 0,
    .nm_filename = nullptr,
    .nm_register_func = Init,
    .nm_modname = "entry",
    .nm_priv = nullptr,
    .reserved = { 0 },
};


extern "C" __attribute__((constructor)) void RegisterEntryModule()
{
    napi_module_register(&nativeModule);
}

接口声明

// index.d.ts
export const callArkTSAsync: (func: Function) => object;

编译配置

CMakeLists.txt文件需要按照如下配置

// CMakeLists.txt
# the minimum version of CMake.
cmake_minimum_required(VERSION 3.4.1)
project(myapplication)


set(NATIVERENDER_ROOT_PATH ${CMAKE_CURRENT_SOURCE_DIR})


if(DEFINED PACKAGE_FIND_FILE)
    include(${PACKAGE_FIND_FILE})
endif()


include_directories(${NATIVERENDER_ROOT_PATH}
                    ${NATIVERENDER_ROOT_PATH}/include)
add_library(entry SHARED hello.cpp)
target_link_libraries(entry PUBLIC libace_napi.z.so)

需要在工程的build-profile.json5文件中进行以下配置

{
    "buildOption" : {
        "arkOptions" : {
            "runtimeOnly" : {
                "sources": [
                    "./src/main/ets/pages/ObjectUtils.ets"
                ]
            }
        }
    }
}

ArkTS代码示例

// index.ets
import testNapi from 'libentry.so';


export function SetTimeout() : Promise<number> {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve(42);
        }, 1000);
    })
}
testNapi.callArkTSAsync(SetTimeout);